Adapter for use in telephone recording

Abstract

An adapter for use in telephone recording of picking-up electric voice signals from a telephone set and outputting them to a sound recording apparatus, comprising a photocoupler having a light emission device that converts electric voice signals picked-up from the telephone set into optical signals and a photoreceiving device for converting the optical signals again into the electric voice signals and outputting them to the sound recording apparatus incorporated into a package case, whereby the telephone set and the recording apparatus are electrically isolated from each other to prevent intrusion of noises from the recording apparatus to the telephone circuit and eliminate the worry of giving unpleasant feeling to the calling party or the worry that the calling party may suspect the contents of telephone call are under recording.

What is claimed is:  
     
         1 . An adapter for use in telephone recording of picking-up electric voice signals from a telephone set and outputting them to a sound recording apparatus, comprising a photocoupler ( 9 ) having a light emission device ( 10 ) that converts electric voice signals picked-up from the telephone set into optical signals and a photoreceiving ( 11 ) device for converting the optical signals again into electric voice signals and outputting them to the sound recording apparatus, the devices being incorporated into a package case ( 12 ).  
     
     
         2 . An adapter for use in telephone recording according to  claim 1 , wherein the light emission device ( 10 ) and the photoreceiving device ( 11 ) are connected individually to the first bias power source ( 13 ) and the second bias power source ( 14 ), respectively, which are isolated electrically from each other.  
     
     
         3 . An adapter for use in telephone recording according to  claim 2 , wherein the first bias power source ( 13 ) connected to the light emission device ( 10 ) comprises a photovoltaic device ( 16 ) for converting a light into electric energy and a light emission device ( 17 ) for irradiating light to the photovoltaic device ( 16 ) thereby causing photovoltaic force therein is connected in parallel with the photoreceiving device ( 11 ) to the second bias power source ( 14 ) connected to the photoreceiving device ( 11 ).